travis.yml: Split Freescale ARM job up more

In order to avoid running into the time limit, split the 32bit and 64bit
Freescale boards into separate jobs.  We could either pass
"freescale & armv8" to buildman or exclude all of the 32bit CPUs.  While
the former is shorter I fear the amount of possible escaping required
would make things less readable.

Signed-off-by: Tom Rini <trini@konsulko.com>